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GNU Lightning
GNU lightning is a free-software library for generating assembly language code at run-time. Version 2.1.3, released in September 2019, supports backends for SPARC (32-bit), x86 (32- and 64-bit), MIPS, ARM (32- and 64-bit), ia64, HPPA, PowerPC (32-bit), Alpha, S390 and RISC-V (64-bit). Advantages over other libraries The features GNU lightning provides make it useful for Just-in-Time Compilation. In comparison to libraries such as LLVM or libJIT, GNU lightning provides only a low-level interface for assembling from a standardized RISC assembly language—loosely based on the SPARC and MIPS architectures—into the target architecture's machine language. Disadvantages It does not provide register allocation, data-flow or control-flow analysis, or optimization. Starting from 2.x, it generates code via intermediate graph, rather than one by one from each of its standardized instructions. This change allows inter-instruction optimization such as register allocation and dea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Project
The GNU Project ( ) is a free software, mass collaboration project announced by Richard Stallman on September 27, 1983. Its goal is to give computer users freedom and control in their use of their computers and Computer hardware, computing devices by collaboratively developing and publishing software that gives everyone the rights to freely run the software, copy and distribute it, study it, and modify it. GNU software grants these rights in GNU General Public License, its license. In order to ensure that the ''entire'' software of a computer grants its users all freedom rights (use, share, study, modify), even the most fundamental and important part, the operating system (including all its numerous utility programs) needed to be free software. Stallman decided to call this operating system ''GNU'' (a recursive acronym meaning "''GNU's not Unix!''"), basing its design on that of Unix, a proprietary operating system. According to its manifesto, the founding goal of the project w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LLVM
LLVM, also called LLVM Core, is a target-independent optimizer and code generator. It can be used to develop a Compiler#Front end, frontend for any programming language and a Compiler#Back end, backend for any instruction set architecture. LLVM is designed around a language-independent specification, language-independent intermediate representation (IR) that serves as a Software portability, portable, high-level assembly language that can be optimizing compiler, optimized with a variety of transformations over multiple passes. The name ''LLVM'' originally stood for ''Low Level Virtual Machine.'' However, the project has since expanded, and the name is no longer an acronym but an orphan initialism. LLVM is written in C++ and is designed for compile-time, Linker (computing), link-time, runtime (program lifecycle phase), runtime, and "idle-time" optimization. Originally implemented for C (programming language), C and C++, the language-agnostic design of LLVM has since spawned a wide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Just-in-time Compilation
In computing, just-in-time (JIT) compilation (also dynamic translation or run-time compilations) is compilation (of computer code) during execution of a program (at run time) rather than before execution. This may consist of source code translation but is more commonly bytecode translation to machine code, which is then executed directly. A system implementing a JIT compiler typically continuously analyses the code being executed and identifies parts of the code where the speedup gained from compilation or recompilation would outweigh the overhead of compiling that code. JIT compilation is a combination of the two traditional approaches to translation to machine code— ahead-of-time compilation (AOT), and interpretation—and combines some advantages and drawbacks of both. Roughly, JIT compilation combines the speed of compiled code with the flexibility of interpretation, with the overhead of an interpreter and the additional overhead of compiling and linking (not j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CLISP
CLISP is an implementation of the programming language Common Lisp originally developed by Bruno Haible and Michael Stoll for the Atari ST. Today it supports the Unix and Microsoft Windows operating systems. CLISP includes an interpreter, a bytecode compiler, debugger, socket interface, high-level foreign language interface, strong internationalization support, and two object systems: Common Lisp Object System (CLOS) and metaobject protocol (MOP). It is written in C and Common Lisp. It is now part of the GNU Project and is free software, available under the terms of the GNU General Public License (GPL). History Haible did not originally intend to distribute CLISP under the GPL, but in a well-publicised email exchange with Richard Stallman, he eventually agreed to do so. The issue at stake was whether CLISP was a derivative work of the GNU readline library. Ports CLISP is extremely portable, running on almost all Unix-based operating systems as well as on Microsoft Windows. Alth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Guile
GNU Ubiquitous Intelligent Language for Extensions (GNU Guile) is the preferred extension language system for the GNU Project and features an implementation of the programming language Scheme. Its first version was released in 1993. In addition to large parts of Scheme standards, Guile Scheme includes modularized extensions for many different programming tasks. For extending programs, Guile offers ''libguile'' which allows the language to be embedded in other programs, and integrated closely through the C language application programming interface (API); similarly, new data types and subroutines defined through the C API can be made available as extensions to Guile. Guile is used in many programs under the GNU project umbrella ( GDB, Make, Guix, GNU TeXmacs, GnuCash, LilyPondLepton-EDA..) but it also sees use outside of that, for example iGoogle's schism Guile Scheme Guile Scheme is a general-purpose, high-level programming language whose flexibility allows expressing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reduced Instruction Set Computing
In electronics and computer science, a reduced instruction set computer (RISC) is a computer architecture designed to simplify the individual instructions given to the computer to accomplish tasks. Compared to the instructions given to a complex instruction set computer (CISC), a RISC computer might require more instructions (more code) in order to accomplish a task because the individual instructions perform simpler operations. The goal is to offset the need to process more instructions by increasing the speed of each instruction, in particular by implementing an instruction pipeline, which may be simpler to achieve given simpler instructions. The key operational concept of the RISC computer is that each instruction performs only one function (e.g. copy a value from memory to a register). The RISC computer usually has many (16 or 32) high-speed, general-purpose registers with a load–store architecture in which the code for the register-register instructions (for performin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Program Optimization
In computer science, program optimization, code optimization, or software optimization is the process of modifying a software system to make some aspect of it work more efficiently or use fewer resources. In general, a computer program may be optimized so that it executes more rapidly, or to make it capable of operating with less memory storage or other resources, or draw less power. Overview Although the term "optimization" is derived from "optimum", achieving a truly optimal system is rare in practice, which is referred to as superoptimization. Optimization typically focuses on improving a system with respect to a specific quality metric rather than making it universally optimal. This often leads to trade-offs, where enhancing one metric may come at the expense of another. One popular example is space-time tradeoff, reducing a program’s execution time by increasing its memory consumption. Conversely, in scenarios where memory is limited, engineers might prioritize a slower ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control-flow Analysis
In computer science, control-flow analysis (CFA) is a static code analysis, static-code-analysis technique for determining the control flow of a program. The control flow is expressed as a control-flow graph (CFG). For both functional programming languages and object-oriented programming languages, the term CFA, and elaborations such as ''k''-CFA, refer to specific algorithms that compute control flow. For many imperative programming languages, the control flow of a program is explicit in a program's source code. As a result, interprocedural analysis, interprocedural control-flow analysis implicitly usually refers to a static analysis technique for determining the receivers of function or method calls in computer programs written in a higher-order programming language. For example, in a programming language with higher-order functions like Scheme (programming language), Scheme, the target of a function call may not be explicit: in the isolated expression (lambda (f) (f x)) it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data-flow Analysis
Data-flow analysis is a technique for gathering information about the possible set of values calculated at various points in a computer program. It forms the foundation for a wide variety of compiler optimizations and program verification techniques. A program's control-flow graph (CFG) is used to determine those parts of a program to which a particular value assigned to a variable might propagate. The information gathered is often used by compilers when optimizing compiler, optimizing a program. A canonical example of a data-flow analysis is reaching definitions. Other commonly used data-flow analyses include live variable analysis, available expressions, constant propagation, and very busy expressions, each serving a distinct purpose in compiler optimization passes. A simple way to perform data-flow analysis of programs is to set up data-flow equations for each node (computer science), node of the control-flow graph and solve them by repeatedly calculating the output from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Register Allocation
In compiler optimization, register allocation is the process of assigning local automatic variables and Expression (computer science), expression results to a limited number of processor registers. Register allocation can happen over a basic block (''local register allocation''), over a whole function/Subroutine, procedure (''global register allocation''), or across function boundaries traversed via call-graph (''interprocedural register allocation''). When done per function/procedure the calling convention may require insertion of save/restore around each Call site, call-site. Context Principle {, class="wikitable floatright" , + Different number of general-purpose registers in the most common architectures , - ! Architecture ! scope="col" , 32 bit ! scope="col" , 64 bit , - ! scope="row" , ARM , 15 , 31 , - ! scope="row" , Intel x86 , 8 , 16 , - ! scope="row" , MIPS , 32 , 32 , - ! scope="row" , POWER/PowerPC , 32 , 32 , - ! scope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DotGNU
DotGNU is a decommissioned part of the GNU Project that started in January 2001 and aimed to provide a free software replacement for Microsoft's .NET Framework. The DotGNU project was run by the Free Software Foundation. Other goals of the project are better support for non-Windows platforms and support for more processors. The main goal of the DotGNU project code base was to provide a class library that is 100% Common Language Specification (CLS) compliant. Main development projects Portable.NET DotGNU Portable.NET, an implementation of the ECMA-335 Common Language Infrastructure (CLI), includes software to compile and run Visual Basic .NET, C#, and C applications that use the .NET base class libraries, XML, and Windows Forms. Portable.NET claims to support various instruction set architectures including x86, PPC, ARM, and SPARC. DGEE DotGNU Execution Environment (DGEE) is a web service server. libJIT libJIT is a just-in-time compilation library for development ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
